Earlier this year, a Twitter user named Paul Hubans shared a screenshot from his 87 year old grandmother’s long-running Animal Crossing session; after four years of daily play, she had logged 3,580 hours—nearly 150 days—of total playtime.

Being able to save progress in a game and return to it later has enabled some amazingly deep experiences. It wasn’t always like this, so how did we get here? Let’s find out by taking a look back at the history of saved games.

(Before we begin, it’s worth pointing out that home computers had a very different set of trade-offs than video game consoles, and saved games were pretty much there from the beginning for computer gamers. This article is focused on the history of saving games on gaming consoles, which was a much more interesting journey.)

In the beginning, there was…not much. Video games were simple, ephemeral experiences—put a quarter into the Pong machine, play until you lose the game, and then move on with your life. The earliest commercial video games were built using discrete logic components, rather than more capable microprocessors[1], and this put a cap on the complexity of the gaming experiences they could offer. Fortunately, for folks living through the dawn of video gaming in the mid-1970s, it was more than exciting enough.

Things began to change in the late 1970s, as the cost of microprocessors fell and home computers became more accessible for the average consumer. This led to the first great divide in video gaming: one one side you had the pure gaming experiences offered in arcades and on dedicated home video consoles, and on the other side you had the the different set of gaming experiences that multi-purpose home computers could offer. Home computers generally lagged far behind dedicated gaming consoles in terms of graphics and sound capabilities, but had an early lead in data storage, at first thanks to floppy disks and later due to capacious hard disks. It would be a long time before game consoles caught up in that regard, keeping the focus on fast arcade action and away from deep, exploratory experiences.

Home video game systems like the Atari 2600 and Nintendo Entertainment System stored their games on cartridges containing ROM chips—read-only memory. Even if game developers wanted to offer more than simple arcade games, there just wasn’t anything for progress to be saved on.